Communication and electrical cable splices are protected from environmental damage by housing in cable splice cases, which protect from moisture, humidity, corrosive environments and the like. Some cable systems employ compressed air in the cables and splice cases to prevent moisture intrusion against the air flow. In these systems, for efficiency and economy, minimizing air loss is advantageous. Thus, cable splice cases can be airtight as well as environmentally sealed.
A variety of cable splice cases are known. Typically, the cases include a cylindrical housing for containing the cable splice, and a pair of circular end plates that fit tightly into the ends of the housing, providing airtight, environmental seals. In one design, the splice case is formed from two half-housings that are installed over suitably prepared end plates.
Communication and electrical cables that extend through openings in the end plates must also be airtight and environmentally sealed against the openings. Various means of sealing are known including compressible collars, O-rings and sealing tape.
A damaged cable line is usually repaired by replacing the entire damaged section of cable lying between two contiguous splice cases. The splice cases are placed in separate manholes. Usually, emergency work restores service to customers before the damaged cable line has been replaced. To replace the cable, both splice cases must be opened and a new section of cable installed. When replacement takes several days, the splice cases must be closed and sealed at the end of each working day. During repair, both damaged and new sections of cable are present and both must be protected by the contiguous splice cases. If the original splice cases are too small to accommodate both sections, larger splice cases must be employed.
Currently, switching to a larger splice case involves replacing both end plates with new, larger end plates. Preparing a new end plate to receive cables in an airtight and environmentally sealed manner is a time consuming task. Further, after repair and removal of the damaged section, the original, splice case (or one of similar dimensions) must be reinstalled due to space limitations in the manhole. Thus, both larger end plates must be changed back to smaller end plates, consuming additional preparation time. Because two contiguous splice cases are involved, and four new end plates are prepared per splice case, in all, eight new end plates must be prepared during cable replacement.
Another problem caused by switching end plates back and forth is further damage to the cables. The process of preparing cables to form air tight, environmental seals can introduce cable deformities, as can the process of installing and removing end plates from around cables. Cable deformities increase the chance of air leaks.